Offset mechanism for saw-mill carriages



3 T T O G S E R P C T T I W E D OFF-SET MECHANISM FOR SAW MILLGARRIAGES.

Patented Feb/28, 1888.

1720611/0]? fie [4427 0 Prescafi.

dwm.

(No Model.) 3 Sheets-Sheet .2.-

DE WITT C. PRESCOTT.

OFFSET MECHANISM FOR SAW MILL GARRIAGE'S.

No. 378,717. Patented Fe 28, 1888'.

awe M202 1 fla 144i! a rascofi'i @EE R. m a

q/vi lhwow/a 3 Sheets-Sheet 3.

(No Model.)

DE WITT O. PRESCOTT.

OFFSET MECHANISM FOR SAWMILL GARRIAGES. No. 378,717.

Patented Feb. 28, 188 8.

ar l

N. PETERS, Phuku-Lilhognpher, Wilmington. v.0

llrrn rricn,

PATENT QFFSET MECHANISM FOR SAW MILL CARRIAGES.

SPECIFICATION forming part of Letters Patent No, 378,717, dated February28, 1888.

Application filed November 9, 1887. Serial No. 254,707. (No model.)

To 00% whom it may concern;

Be it known that I, DE I/VITT CLINTON PRES- eoTT, a citizen of theUnited States, residing at Marinette, in the county of Marinette andState of lVisconsin, have invented a certain new and useful Improvementin Offset Mechanism for Saw-Mill Carriages, which is fully set forth inthe following specification, reference being had to the accompanyingdrawings, in which- Figure l is a plan view of a sawmill carriageembodying my invention; Fig. 2, ascotional view taken on the line 1 l ofFig. 1,and on an enlarged scale; Fig. 3, a transverse sectional viewtaken on the line 2 2 of Fig. 1; Fig. 4, a central transverse sectionalview of the cam-shifting device; Fig. 5, a plan view of the elements ofthe shifting mechanism detached; Fig. 6, a sectional view of the same,taken on the line 3 3 of Fig. 5; Fig. 7, a view of a modified form ofshifting device; Fig. 8, a plan view of the mechanism on the carriageproper co-operating therewith; Fig. 9, a sectional view taken on theline at 4. of Fig. 7, and looking in the direction of the arrow; andFig. a detail sectional view taken on the line 5 5 of Fig. 8.

Like letters refer to like parts in all the figures of the drawings.

My invention relates to saw-mill carriages,

and more particularly to that class in which.

the carriage is provided with automatic means for shifting the log clearof the saw upon its return movement, and advancing the same to itsoriginal position upon its forward movement.

My present invention is in the nature of an improvement upon theapparatus setforth in an application for Letters Patent filed by me June9, 1887, Serial N 0. 240,834, and has for its object to improve theconstruction therein set forth for imparting movement to the camshiftingdevice in order to render the same more simple, cheap, and efficient inoperation.

I will now proceed to describe a construction in which I have carriedout my invention in a practical way, and will then particularly pointout in the claims thosefeatures which I deem to be new and desire tosecure by Letters Patent.

In the drawings, A represents the frame of the sawmill carriage, thisframe being of any approved construction, and being provided with theusual means for securing the log in position thereon and for setting itup to the saw at each cut. This frame is mounted on a series of truckscomposed of axles 13, each pro vided with wheels I) and b, securedthereon and revolving therewith. These wheels travel upon the rails Gand O, the said wheels and rails being constructed in any approved form,although I prefer that shown, in which one of the rails, as G, isprovided with a projecting rib, while the corresponding wheel, I), is

grooved to fit upon the rib and prevent lateral displacement of thetrucks.

The carriage A is free to move laterally upon the axles,so as to clearthe log of the saw upon the return movement of the carriagaand allow itto be moved up into position again upon the forward movement. In orderto effect this lateral movement of the carriage, I employ cam-shiftingdevices mounted on one or more of the axles and constructed substantially as in my application for Letters Patent hereinbefore referred to.In this construction D represents a sleeve mounted loosely on theaxle,so as to be capable of a rocking or oscillating movement around thesame, and provided on its upper side with a cam-groovaD, formed by meansof parallel inclined projections D A transverse beam, E, on thecarriageframe A is provided with a roller, E, which enters between theinclined projections D", and thus engages the cam-groove D formedthereby.

These parts just described are constructed substantially in the samemanner as set forth in my application hereinbefore referred to, andtherefore need no detail description here.

In order to operate the sleeve D, I employ collars F, mounted on theaxle B at each end of the sleeve, fixed on the said axle so as to rotatetherewith, and having a frictional contact with the ends of the sleevesufficient to actuate the same within the limits of its motion. Thecollars F are adjustable upon the axle B,being secured thereon afteradjustment by means of setscrews f. In order to obtain an efficientfriction-surface, I form upon each collar a friction-disk, F, providedwitha pro jecting marginal flange, f, and I form upon the adjacent endof the sleeve 1) a correspond ing friction-disk, D over which the flangef projects slightly when the parts are in position, so as to protect thefriction-surfaces. Between the friction-disks F and D I prefer toemploya washer, F constructed of wood, vulcanized fiber, or othersuitable material, which serves to increase the friction between thedisks, this washer lying in a suitable groove, f, in the friction-disksF. In order to provide means for adjusting the frictional contactbetween the collars and the sleeve. independently of the adjustment ofthe collars on the axle B, I make the groovef in one of thefriction-disks F of increased depth, and locate therein a metallicannulus, F, against the back of which bear springs 1', arranged insuitable housings, F, provided with screwcaps f by means of which thepressure of the springs upon the annulus F may be nicely regulated. Eachof the sleeves D is provided with a downwardly-extending arm, D*, to thelower end of which is pivoted one end of a connecting-rod, G, the otherend of which is connected to a vibrating arm, H, mounted in a suitablebearing, H, on the frame A.

In the construction shown in Figs. 1 and 2, in which two cam-shiftingdevices are employed, one at each end of the carriage-frame, the twoconnecting-rods G are both connected to the same vibrating arm H,whicharm is located at about the middle of the carriageframe.

H represents adjustable stops, constructed substantially as in myapplication for Letters Patent hereinbefore referred to, and serving bytheir contact with the projecting upper end of the vibrating arm H tolimit the motion of the same, and consequently the motion of the sleevesD.

H? represents a lock consisting of an L- shaped arm pivoted on thehousing of one'of the stops H or any other suitable base, and serving,when hooked or caught over the upper end of the vibrating arm H, to lockthe 1 convenient reach of the operator,who is seated upon the carriageat this point and may reach the lock without leaving his seat. I11 case,however, a more compact form is desirable, as, for instance, where thedevice is to be applied to a saw mill carriage already in usein whichinstance it is desirable to have the whole device self-contained andcapable of ready application as a whole-I may employ the modified formof apparatus shown in Figs. 7 to 10 of the drawings. In thisconstruction the stops H are mounted on the cross-beam E, on oppositesides thereof, and also preferably on opposite sides of the axis of theroller E. I also form upon the sleeve D projecting wings I, arranged onopposite sides thereof, as

on the beam E, and is provided with a handle I or lever, j, foroperating the same. This locking-arm may be swung down into the positionshown in full lines in Fig. 9 of the drawings, to bear upon the arm I,and thus lock the cam-shifting device during the return-motion of thecarriage; or it may be swung out into the position shown in dottedlines, when the said shifting device is free to operate.

The operation of the apparatus is as follows; lVhen the carriage startsupon its forward travel to make the first cut, the collars F will, byreason oftheir frictional engagement with the sleeves D, rotate the samealong with the axles B to the extent permitted by the stops H, and thismotion of the sleeves will, by reason of the cam-grooves thereon, impartto the frameA a lateral movement upon the axles B sufficient to presentthe log to the saw in proper position to make the first cut. When thecarriage has completed its forward journey and the direction of itstravel is reversed, the collars F will, by reason of their engagementwith the sleeves D, impart a partial movement of rotation to saidsleeves in the reverse direction, and will move the frame A bodily uponthe axles away from the saw, thereby clearing the log from the saw andpreventing any contact between them during the return movement of thecarriage. It will be observed that by arranging the frictioncollars atthe ends of the sleeves I not only obtain a much more simple and compactdevice, but I also utilize the lateral thrust which the rollers E exertupon the inclines D to press the sleeves more firmly against thefriction-collars, and thus obtain a better contact, whereby theefficiency of the device is increased. It will be understood,ofcourse,that

when the sleeves have reached the limit of their motion in eitherdirection the frictional contact between the collars and the saidsleeves is not sufficient to prevent the free ropass out of the kerfalready formed, and this is effected by locking the shifting device bythe means already described, so that when the motion of the carriage isreversed no lateral movement of the carriage-frame will occur.

It is obvious that various modifications in the details of constructionmay be made with- Having thus described my invention, what I claim asnew, and desire to secure by Letters Patent, is

1. In a saw-mill carriage, the combination, with the truck-axles, of thecarriage-frame capable of lateral movement on the axles, one or morecam-shifting devices mounted loosely on the axles, correspondingprojections connectcd to the carriage-frame and engaging saidcam-shifting devices, and friction-collars secured on the axles at eachend of the camshifting devices to operate the same, substantially as andfor the purposes specified.

2. In a saw-mill carriage, the combination, with the trucleaxles, of thecarriage-frame eapable of lateral movement on the axles, one or moreeam-shifting devices mounted loosely on the axles, correspondingprojections on the carriage engaging said earn-shifting devices, stopsto limit the motion of the cam-shifting devices, and friction-collarssecured on the axles at each end of the cam-shiftin g devices to operatethe same, substantially as and for the purposes specified.

3. In a saw-rnill carriage, the combination, with the truck-axles andthe carriage-frame capable of lateral motion thereon and provided with aprojection, of a sleeve mounted loosely on one or more of the axles andprovided with a cam-groove With which the said projection engages,friction-disks on the ends of the said sleeve, and collars secured onthe axle at each end of the sleeve and provided with friction-disks tobear against the corresponding disks on the sleeve, substantially as andfor the purposes specified.

4. Thecombination,withthetruck-axleBand the carriage-frame laterallymovable thereon and provided with a suitable projection, of the sleeveD, mounted loosely on the axle and provided with a cam-groove to receivethe projection, the end frietion-disks,D the collars F, secured on saidaxle at each end of the sleeve and having flanged disks F, and thewashers F arranged between the said disks, substantially as and for thepurposes specified.

5. The combination, with the axle B, sleeve D,with friction-disks D andcollars F, with friction-disks F, of the washers Fflthe annulus F,arranged behind one of said washers, and the springs f of adj ustabletension, for regulating the friction, substantially as and for thepurposes specified.

DE WI'lT CLINTON PRESCOTT,

\Vitnesses:

W. P. Mans, JOHN J. ANDREW.

